It is proposed to identify, isolate, and characterize those regulatory factors which govern the initiation and orderly occurrence of events which lead to morphogenetic change (sporulation) in Bacillus subtilis. Identification will be attempted by addition of cell supernate fractions to an in vitro RNA synthesizing (transcribing) system containing RNA polymerase from various stages of morphogenesis. The resulting radioactive RNA product will be subjected to hybridization competition using non-radioactive, in vivo synthesized RNA isolated from cells in various stages of sporulation. The patterns of competition, based on experiments already completed, will serve to identify the presence, in the radioactive RNA product, of sporulation-specific RNA. Cell fractions which stimulate the transcribing system to synthesize sporulation-specific RNA will be subjected to further purification and characterization to specifically elucidate the role of these factors. Characterization will include, assuming the factors to be protein, determination of molecular weight, subunit structure, and nature of the interaction with DNA or with the polymerase.